【题文】方程的解为
题型:难度:来源:
【题文】方程
![](http://img.shitiku.com.cn/uploads/allimg/20200331/20200331020610-23840.png)
的解为
答案
【答案】
![](http://img.shitiku.com.cn/uploads/allimg/20200331/20200331020610-80470.png)
解析
【解析】
试题分析:对数方程一般要化为
![](http://img.shitiku.com.cn/uploads/allimg/20200331/20200331020610-35839.png)
或
![](http://img.shitiku.com.cn/uploads/allimg/20200331/20200331020611-84806.png)
的形式,然后根据对数的函数的性质化对数方程为代数方程,本题可化为
![](http://img.shitiku.com.cn/uploads/allimg/20200331/20200331020611-54728.png)
,即
![](http://img.shitiku.com.cn/uploads/allimg/20200331/20200331020611-79515.png)
,解得
![](http://img.shitiku.com.cn/uploads/allimg/20200331/20200331020610-80470.png)
.
考点:解对数方程.
举一反三
【题文】设
a=0.5
0.5,
b=0.3
0.5,
c=log
0.30.2,则
a,
b,
c的大小关系是( ).
A.a>b>c | B.a<b<c |
C.b<a<c | D.a<c<b |
【题文】设
a=log
36,
b=log
510,
c=log
714,则 ( ).
A.c>b>a | B.b>c>a |
C.a>c>b | D.a>b>c |
【题文】已知函数
f(
x)=
![](http://img.shitiku.com.cn/uploads/allimg/20200331/20200331015704-46293.png)
则
f![](http://img.shitiku.com.cn/uploads/allimg/20200331/20200331015704-27615.png)
= ( ).
A.4 | B.![](http://img.shitiku.com.cn/uploads/allimg/20200331/20200331015705-37220.png) | C.-4 | D.-![](http://img.shitiku.com.cn/uploads/allimg/20200331/20200331015705-37220.png) |
【题文】设
a=log
32,
b=log
52,
c=log
23,则( ).
A.a>c>b | B.b>c>a | C.c>b>a | D.c>a>b |
【题文】已知函数
f(
x)=
![](http://img.shitiku.com.cn/uploads/allimg/20200331/20200331014807-89691.png)
则
f![](http://img.shitiku.com.cn/uploads/allimg/20200331/20200331014807-27466.png)
= ( ).
A.4 | B.![](http://img.shitiku.com.cn/uploads/allimg/20200331/20200331014807-79688.png) | C.-4 | D.-![](http://img.shitiku.com.cn/uploads/allimg/20200331/20200331014807-79688.png) |
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